A so-called peer-to-peer telephone system is described in WO2005/009019. In such a system, a plurality of end users can be connected for communication purposes via a communications structure, for example the internet or world wide web. The communications structure is substantially decentralised with regard to communication route switching therein for connecting the end users. That is, the end users can establish their own communication routes through the structure based on exchange of one or more authorisation certificates (user identity certificates—UIC) to acquire access to the structure. The structure includes an administration arrangement issuing the certificates to the end users. One such phone system exists under the trade name SKYPE™.
In order to use such a phone system, each user terminal installs client software for making calls. A user terminal can for example be a personal computer (PC). The client software itself is not principally the subject of this invention and so is not described in detail herein. It is capable of receiving a phone number for an end user in a standardised format and implementing a call to that user. It also has a registry for holding user names and numbers, so that a name, instead of a number, can be used to instigate a call. To allow a user to use the client software, it causes a display of the personal computer to display various images with which a user can interact using a conventional user interface such as a keyboard or mouse and cursor arrangement. This includes the display of a dialpad with numbers by means of which a user can dial the number that he wishes to call.
The SKYPE peer-to-peer phone system is widely used, but some issues have arisen which are addressed herein to simplify use of the system for users, particularly but not exclusively new users. In particular, users can have a difficulty in selecting the correct format of numbers to dial using the dialpad. This is particularly the case when dialling International numbers, that is dialling to reach a user who is outside a country where the dialling user is located.